function openCentered(url,width,height,attributes)
{
	var h,w;
	var x,y;
	h=window.screen.height;
	w=window.screen.width;
	x = (w - width)/2
	y = (h - height)/2
	var mywin=window.open(url,"opener","left=" + x + ",top=" +  y + ",width=" + width + ",height=" + height+ "," + attributes )
	//mywin.moveTo(x,y)
	return mywin;
}